Russia will launch the world's first floating nuclear reactor and send it on an epic journey across the Arctic on Friday, despite environmentalists warning of serious risks to the region.Loaded with nuclear fuel, the Akademik Lomonosov will leave the Arctic port of Murmansk to begin its 5,000 kilometre (3,000-mile) voyage to northeastern Siberia.

Nuclear agency Rosatom says the reactor is a simpler alternative to building a conventional plant on ground that is frozen all year round, and it intends to sell such reactors abroad.